InternationalBioNTech confirms a third dose of Pfizer vaccine will be needed to maintain immunityAlbert Castellví Roca29-04-2021
![Vaccines used in a file image.](data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 9"%3E%3C/svg%3E)